ting ley



Nav. 23 1926. 1,608,145A

B. H. TINGLEY DUPLEX ADDING MEGHANISM Filed July 26, 1923 5 Sheets-Sheet l IN VENTOR A TTORNE) Nov. 23 1926.

` B. H. TINGLEY DUPLEX ADDING MEGHANISM Filed July 2S. 1923 3 Sheds-Sheet 2 Ncv. 23 1926. 1,608,145

B. H. TINGLEY DUPLEX ADDING' MECHANISM Filed Ju'ly 2e. 192.3 5 sheets-sheet s ff ggg s 35 /NI/ENTOR Patented Nov. 23, 1926.

Y UNITED STATES PATENT OFFICE.

BRUCE H. TINGLEY, OF CINCINNATI, OHIO, ASSIGNOB T0 THE DALTON ADDING HA- CHINE COMPANY, 0F CINCINNATI, OHIO, CORPORATION OF OHIO.

DUPLEX ADDING MEGHANISM.

Application led .Tuly 26, 1923. Serial No. 853,899.

This invention relatesto the provision, in an adding machine, of certain mechanism which gives to the adding machine the capacity not only to accumulate and add items and secure a total therefrom but also to accumulate a series of totals and to do this in such a way that either total may be cleared and a new total started without disturbing the other. These results are obtained with out disturbance of the mechanism ordinarily employed in the accumulatingsection of an adding machine, by providing additional accumulating mechanism connected and operable in `harmony with the regular accumulating mechanism, so that items in troduced into the machine will be accumulated by both mechanisms, provision being made, however, for the takin of totals from either set of' mechanisms without interference with the other.

The mechanism, by way of exempliication, is illustrated in connection with cer tain adding machine parts or mechanisms of the kind and style used in the well known Dalton adding machine, although it will be understood that the invention is not limited to such an association.

In the drawings:

Figure 1 is a side sectional elevation of a Dalton adding machine, -showing the relative position of the special duplex adding mechanism, when the machine is normal;

Fig. 2 is a rear view, showing the duplex mechanism;

Fig. 3 is a side fragmentary view of the ladding rack coupling mechanism released for taking a total in the left hand set of wheels Ain which the accumulation of the series of totals are'stored;

Fig. 4 is a view ofthe adding racks released for taking a total in the right hand set of wheels which accumulate items;

Figf is a view of the adding racks coupled'together at the start of an adding operation; and

Fig. 6l is a rear view of the adding rack coupling mechanism.

Since with this duplex mechanism one of the purposes is the accumulation of a total of a series of totals, without a separate transfer operation, and to do it with the regular accumulating section of an ordinary adding machine, wherein all accumulating wheels are mounted on a single shaft and controlled by the regular accumulating wheel meshing mechanism, it isnecessary to accumulate each item at the same time, in each set of wheels, both of which are mounted on the same shaft.

The details of the adding wheels with their associated mechanisms are not shown 1n the drawings, since they are of standard type and operate in the usual manner, save for the fact that in the present invention two sets of adding wheels rather than one are em loyed.

As viewed from the front, the ri ht hand group of mechanisms, includin t e usual printing sectors, racks, and ad ing wheels, constitute the regular adding andv println elements of an adding machine of. we known construction. The left hand of elements, including the racks, printing sectors, and wheels, constitute the supplemental mechanisms peculiar tothe machine of the present invention, and it is this group of mechanisms which enables the machine to perform its special function of duplex adding and totalizing.

Referring now briefly to the ri ht hand or standard group of mechanisms, 1t will be noted that 1t consists of a series of racks 10,

group v between the sidewalls 13 of the machine frame. Each of the sectors carries at its upper end an arm Y14 to which is secured a spring 15 which tends to depress the arm and lift the sector, the usual cross bail 16 being provided to hold the arms in their normal retracted position. The sectors and associated racks are connected. by means of springs 17 of the usual character, so that the associated elements will act in unison in a manner well understood in the art.

The racks and sectors, when released by the bail, will advance until stopped by the engagement of the' heels 18 (which are on the right hand group of sectors only) against the stops in a stop carriage not shown, and upon the return movement will be engaged by the set of adding wheels to store up an item commensurate with the adtension 19, the upper ends of which are bent laterally to the left to afford a series of neste-d arms 2O (sce Fig. 2) which lie one beneath the other so as to avoid interference. The outer ends 21 of the several arms, save thel first, are upturncd in progressively increasing degree, so that all of the arms will terminate in the same horizontal plane and in positions immediately to the rear of the respective elements of the left hand group of mechanisms, which correspond in number and in function'to the elements composing the right hand group, as viewed from the front of the machine.

The left hand group consists of a series of racks 22, one corresponding with each of the right hand racks, and each of the racks 22 has pivoted thereto a coupler 23 provided with a lug 24 adapted to engage the terminus 21 of a corresponding arm when lowered, so that with the parts thus adjusted the left hand racks will follow and conform to the movements of the corresponding right hand racks under the influence of like springs in preparation for the accumulation in the left hand adding wheels of an amount commensurate with that accumulated in the right hand wheels. The pivoted couplers 23 are all released from the arms when the machine is normal, as in Fig. 1. This is accomplished by the provision of a stud 25 attached to the rear end of each coupler, which studs ride in arcuate slots 26 formed in the coupler guides 27, one for each of the adding racks in the left hand series. The coupler guides are spaced an equal distance apart and are held in position by three tie rods 28, 29, 30, the ends of which are rigidly entered into sid-e plates 31 which depend from andare pivoted upon a cross shaft 32 carried by brackets 33 inwardly extending from a truss plate 34 mounted upon the rear wall of the machine. This arrangement afords a cradle having a series of guides providing arcuate slots into which the studs 25 are adapted to ride back and forth as the cradle is adjusted, and as thel racksare operated.

The left hand plate is extended inthe form of a bell crank to provide an arm 36 to which is pivoted a vertical slide bar 37 provided with a laterally projecting stud 38 which is engaged by the bifurcated rear end of a lever 39 centrally pivoted at the point 40, the forward end of which lever lies in position to be engaged by the head of a pivot stud 41 carried at the uppery end of a link 42` which link is pivoted to a crank arm 43 rigid upon the main operating shaft 44. When the main shaft is in its normal position, as in Fig. 1, the pivot stud 41 bearinf.` upon the forward end of the lever 39 will hold` the same in depressed position, with the r' ar end of the lever elevated to lift the sli e bar 37, which in turn lifts the cradle composed of the slotted guide bars and thereby serves to disengage the series of couplers from the arms on the right hand group of racks, which disengagement of the parts is essential in the taking of totals, in

order that either total may be taken without disturbing the other.

As soon as the main shaft moves forward when items are added, the link 42 will move upwardly, thereby releasing the engagement of the stud 41 with the forward end of the lever 39, which allowsthe rear end to descend with the slide bar under the pull of a spring 45 secured to one of the pivoted end plates 31. `This effects a lowering of the couplers into engagement with the respective arm extensions 2l of the right hand group of racks, so that the two groups of racks will advance and be stopped in unison in positions to introduce the intended item into the machine. The rearward movement of the cradle under the pull of the spring 45 is limited by the engagement of a lip 4G against a stud 47 on the rear truss plate 34.

When the main shaft is restored to normal position after each adding operation,

the coupler cradle will be lifted in the mang ner described, and each rack will be disengaged from its co-operating rack, so that either may complete its carrying operation by moving rearwardly in a manner well understood in the art, without interfering with the companion rack.

When a total of the added items which have been accumulated by the right hand set of racks is desired, a total key 48 is operated in the usual Way to effect a rearward movement of a total link 49. The forward end 50 of the total link isupturned and pivoted at the point 51 to an arm 52 upstanding from a rock shaft to which the lower end of the total key lever 5t is rigidly secured, so that a rocking of the shaft by a movement of the total key will result in a rearward thrust of the total link 49.

In moving to the rear, the total link causes the accumulating wheel mechanism to be lifted vinto mesh with the racks on the for ward movement thereof instead of on the return movement, as indicated, for instance` inthe Hopkins Patent No. 1,039,130 of September 24, 1912. The total link has slidably mounted thereon a slide plate 53 provided with a depending finger 5,9 which bears against the upper surface of a detent plate 60, so that, as the slide' plate moves to the rear, the rear upper edge of the plate will be depressed to release the heels 18 of the right hand racks, which, however, are held against advancement by the cross bail 16 until thebail begins to move as the han* dle is operated. y

' The slide plate is acted upon by a spring 61, the rearward end of which is secured to a headed stud ,62'on the total nlink, which stud passes through a. slot` 63 1n the slide plate, and the rear end of the ring -is connected directly these parts will normallyl move 1n umson under spring tension: A hp 64 1s turned. to the right from the rear end of the slide plate 58, and the rearward movement thereof causes the lip to contact a stud 65 on an arm 66, which constitutes a fportion of a bracket 67 which is rigidly astened to a horizontal rock shaft 68 ivoted in sultable brackets 69 and 70 (see ig. 2).

The rocking movement imparted to the shaft 53 by the depression of the total key causes the bracket to move up;and contact the projections 71 that extend down from the left hand group of racks, as 1n Fig. 4, and this contact serves to block any forward movement that they would otherwise make when the main shaft is operated. In the meantime the bail 16,V moving rearwardly as the handle is operated, permits the right hand racks to move forward and register a total of items in the accumulating wheels controlling the right hand racks. Thus 1t will be seen that a total of the added ltems accumulated by the racks on the right hand set may be cleared without disturbing the total accumulated by the left hand racks, and the process of adding the items for the right hand racks may be continued and cleared as often as necessary, with the result that the same items introduced into and successively clearedfrom the right hand set of adding wheels will be also introduced vvinto the left hand adding wheels, but not cleared therefrom, so that the left hand adding wheels will contain a total of all the totals taken from the right hand wheels.

When'it is desired to secure a grand total of the accumulated totals stored in the left hand wheels, this may be obtained by depressing a special preparatory key 72 which operates a slide bar 73 provided at its rear end with a hooked finger 74 which, when the special key is depressed, will move to a position in which it overlies the bent arm 75 rearwardly extending from the rock shaft 68, so that with the parts in this position the shaft' will be blocked against rocking as the total key is depressed, thereby preventing the bracket from moving to a position to engage the project-ions 71 on the left hand racks. With the parts thus adjusted, when the total key is depressed, it will prepare the mechanisms for a total `taking operation, and in this instance all of the left hand racks will be free to advance, so that a grand Ytotal will be taken. The depression of the total key will cause the bent arm 75 to engage the hooked finger 74, so that this vwill prevent the restoration of the special key 72, even though it be released from ressure.

When the movement of the bracket 67 is tov the slide p ate, so that thereafter serves to stretch the spring 61.

arrested it willhave the effect of blocking Y any further movement of the slide plate 56, which is slidably mounted in order to permit contin'ued movement of the total link which However, with the slide plate 58 thus blocked it will not advance sufficiently' to disengage the detent plate from the heels of the right hand racks, so that these racks will remain stationary and the left hand racks alone be permitted to'advance .for the pur-` .pose of taking the grand total. Since in ing wheels, it is necessary to make provision during the grand totalling operation against the engagement of the couplers which unite the racks of the right hand group with the corresponding racks of the left hand group.

To effect this result the total link is provided near its rear end with a laterally extending stud 76 (see Fig. 2) which, when the link movesvto the rear, will align under the lower end of the vertical slide bar 37 which controls the movements of the couplers, so that with the parts in this position the slide bar 37k will be blocked against downward movement under the tension o f the spring 45 when the main handle is operated, thereby holding the couplers free from the arms 20 and permitting the left hand racks to move to the degree permitted by the individual left hand adding wheels with which they are associated during the total taking operation. A grand total may thus be taken without disturbing any lesser total which may have accumulated in the right hand adding wheels, since during this operation any advance of the right hand racks will be blocked by the detent plate which remains elevated and 1n engagement with the rack heels 18.

A brief summary of the ope-rations is as follows: When the ordinary numeral keys are depressed the usual 'stops will be set up in the traveling carriage (not shown) until an entire item has been set up, after which the vmain shaft will be operated by the handle, which operation will cause a lowering of the couplers to engage the laterally extending arms on the racks composing the right hand group, so that as the universal bail 16 vadvances under the control of the handle all and each rightl hand rack will per-V the right hand group the total key 48 will be depressed or moved rearwardly, and the total link thrust to the rear, which will have the effect, first, of depressing the detent plate and releasing the heels of the right hand racks, and, second, of moving the swinging bracket 67 to a position to engage with an prevent any movement of the left hand racks. With the parts thus adjusted the operation of the handle will result in the taking of a total from the right hand group of adding wheels without in any way disturbing the amounts accumulated in the left hand group of adding wheels.

Vhen it is desired to take a grand total the preparatory key 72 is iirst depressed or moved to the rear, which has the edect of blocking the movement of the bracket 67, and results in a blocking of the mechanism for actuating the detent blade 60, so that the right hand racks will be held against movement and the left hand racks released, after which a depression of the total key will block the engagement of the couplers and permit the left hand racks alone to advance when released by the universal bail, so that in those circumstances the left hand racks, in mesh with the left hand adding wheels, will advance to their respective limits oi* movement and a grand total will be secured without disturbing the lesser total accumulated in the right hand wheels.

The mechanism is one which .utilizes the regulation setting up mechanism of the characters shown in the Hopkins Patent No. 1,039,139 of September 24, 1912, in the performance of a duplex operation, and increases its capacity without substantial change or modification .ot the mechanisms Vregularly employed in adding machine construction, and without materially increasing the bulk or otherwise modifying the gen eral structure of the adding machine as a whole.

I claim:

1. In mechanism of the class described, the combination of two groups of racks, connections between the corresponding racks of each group for imparting like movements to corresponding racks, and means for disabling said connections to permit movements of the racks of one group only, SubstantiallyI as described.

2. In mechanism of the class described, the combination of two groups of racks, connections between the corresponding racks of each group for imparting like movements to corresponding racks, and total taking means for disabling said connections to permit movements of the racks of one group only, substantially as described.

3. In mechanism of the class described, the combination of two groups of racks. connections between the corresponding racks of each group for imparting like movements to ments or' the racks of one group only,

correspondin racks, total taking means for disabling sai connections to permit moveand preparatory means associated with the total taking means for regulating thev latter to take a total from the alternate group of racks, substantially as described.

4. In mechanism of the class described, the combination of two groups of racks moving in parallel paths, connections between each rack of one group and the corresponding rack ot' the other group, for securing uniform movements in corresponding racks,

' and, means for disabling said connections to permit one group of racks alone to move, substantially as described.

5. In mechanism of the class described, the combination of two groups of racks moving in parallel paths, connections between each rack of one group and the correspending rack of the other group, for securing uniorm movements in corresponding racks, and means for disabling said connections to permit one group of racks alone to move, the connections being in the form of arms laterally extending from one group of racks and adapted to individually engage the corresponding racks of the other group, substantially as described.

6. In mechanism ofthe class described, the combination of two groups of laterally adjacent racks moving in parallel paths, the racks of one group being provided with laterally extending arms individually terminating in alignment with corresponding racks of the other group, a coupler for each of the racks of the second group, adapted to engage with the associated arm, and means for moving said couplers to non-engaging position, substantially as described.

7. In mechanism of the class described, the combination'of two groups of laterally adjacent racks moving in parallel paths, the racks of one (group being provided with laterally exten ing arms individually terminating in alignment with corresponding racks of the other group, a coupler for each of the racks of the second group, adapted to engage with the associated arm, and means for moving said couplers to non-engaging position, said means including a slotted slide plate for each coupler,substantially as described.

8. In mechanism of the class described, the combination of two groups of laterally adjacent racks movin in parallel paths, the racks of one group eing provided with laterally extendlng arms, each arm being associated with the corresponding rack in the other group, a pivoted coupler for each rack in the second group, adapted when lowered to engage the corresponding arm, a slotted guide p ate for each of the couplers, and means for moving the guide plates to lift the couplers to non-engaging position and perconnections between said sha mit independent movement of the 'racks in' the second roup, substantially as described.

9. In mec anism of the class described, the combination of two groups of laterally adjacent racks moving in parallel aths, the racks of one group being provide 1 with laterally extending arms, each arm bein associated with thecorresponding rack ml the other group, a pivoted coupler for eachrack in the second group, ada ted when lowered to enga e the correspon ing arm, a slotted guide p ate for each of the couplers, means for moving the guide plates to lift the couplers to non-engaging position and permit independent movement of the racks 1n the second group, a main operatin shaft, and and said guide plate operatin means for normally efecting engagement tween the couplers and the rack arms with each operation of the shaft, substantially as described.

10. In mechanism of the class described,

4the combination of two groups of laterally adjacent racks moving in parallel paths, the racks of one groupbeing providedwith lat-A erally extending arms, each arm being associated with the corresponding rack 1n the other group, a pivoted coupler for each rack in the second group, adapted when lowered to enga e the corresponding arm, a slotted guide p ate for each of the couplers, means for moving the guide plates to lift the couplers to non-engaging position and permit independent movement of the racks of the second group, a main operating shaft, con'- nections between said shaft and said guide plate operating means for normally eil'ecting engagement between the couplers and the rack arms with each operation of the shaft, and means for preventin said engagement during the operation of t e shaft, substantially as described. p

11. In mechanism of the class described,

the combination of two groups of laterally' adjacent racks moving in parallel lines, each rack of tlie rst group being provided with a laterally7 extending arm associated with the corresponding rack of the second group, a coupler carried by each rack ofthe second group and adapted to engage said arm, an operating shaft and connections between said operating shaft and each coupler for normally effecting engagement of the coupler with the associated arm during each operation of the shaft, substantially as described. 12. In mechanism of the class described, the combination of two groups of laterall adjacent racks moving in arallel lines, eac i rack of the first group being provided with a laterally extending arm associated with the corresponding racks of the second group, a coupler carried by each rack of the second group and adapted to engage said arm, an operating shaft, connections between said o erating shaft and each coupler for normal y a effecting engagement of the coupler with the associated arm during each operation of the shaft, and adjust-able means for withholding said engagement during the operation of the shaft, substantially as described.

f 13. In mechanism of the class described, the combination of two groups of laterall adjacent racks moving in parallel lines, eac rack of the rst group being provided with a laterally extending arm associated with the corresponding rack of the second group, a coupler carried by each rack of the second group and adapted to engage said arm, an loperatin shaft, connections between said operating s laft and each coupler for normally effecting engagement of the coupler with 4the associated arm during each operation of the shaft, adjustable means for withholdin said engagement v during the operation o the shaft, adjustable means for locking the racks of the first group against advance movement, and adjustable means for locking the racks of the second group against advance movement, substantially as described.

14. In mechanism of the class described, the combination of two groups of laterally adjacent racks moving in parallel lines, con-,.

nections for each of the racks of the firstl group with the corresponding rack of the second group, for imparting like movements to corresponding racks, means for disabling said connections, means for locking the racks of the first roup against advance movement, and means for locking the racks of the second group against advance movement, substantially as described.

15. In mechanism of the class described, the combination of two groups of laterally adjacent racks movingl in parallel lines,

lconnections for each of the racks of the first group with the corresponding rack of the second group, for imparting like movements to corresponding racks, means for disabling said connections, means for locking the racks of the first group against advance movement, means for locking the racks of the second group against advance movement, and means for locking the `locking means of one group while `unlocking the locking means of the other group, substantially as described.

16. In mechanism of the class described, the combination of two groups of racks in juxtaposed relation, connections carried by each rack of the first group and adapted to engage witli the corresponding racks of the second group, a main shaft, connections bctween the main shaft and the rack connections for normally bringing the rack connections into engaged relation during each operation of the main shaft, a tot-al taking device, a lock for all of the racks in the first group, adapted to be disengaged by the active movement of the total taking device, and lock for all of the racks Aofthe second group, adapted to be engaged by the active movement of the total taking device; substantially as described. D

17. In mechanism of the class described, the combination of two groups of racks in juxtaposed relation, connections carried by each rack of the first group and adapted to engage with the corres onding rack of the second vroup, a main s aft, connections between the main shaft and the rack connections for normally bringing the rack connections into engaged relation during each operation of the main shaft, a total tak1ng device, a lock for all of the racks 1n the first group, adapted to be disengaged by the active movement of the total taking device, a lock for all of the racks of the second group, adapted to be engaged by the active movement of the total takin@ device, and a reparatory device adapte when actuate in advance of the actuation of the total taking device to reverse the action of the latter on the respective locking devices, substantially as described.

18. In mechanism of the class described, the combination of two groups of racks in juxtaposed relation, the racks of the first group being provided with laterally extending arms, each associated with a corresponding rack of the second group, a coupler carried by each rack in the second grou and adapted to engage with the associate arm, a main shaft, means operable `by the movement of the main shaft for permitting the couplers to move to engaging position, locking means for all of the racks of the first group, locking means for all of the racks of the second group, and a total link adapted when normally moved to disengage the locking devices of the first group and engage the lockin devices of the second group, and to hold t efcouplers out of engaging relation during the movement of the operating shaft, substantially as described.

19. In mechanism of the class described, the combination of two groups or racks in juxtaposed relation, the racks of the first group being provided with laterally extending arms, each associated with a corresponding rack of the second group, a coupler carried by each rack in the second group and adapted to engage with the associated arm, a main shaft, means o erable by the movement of the main sha t for permitting the couplers to move to engaging position, locking means for all of the racks of the first group, locking means for all of the racks of the second group, a total link adapted when normally moved to disengage the locking devices of the first group and engage the locking devices of the second group and to hold the couplers out of engaging relation during the movement of the operating shaft, and a preparatory device adapted when actuated in advance of a movement of the total link to reverse the effect of the latter on the respective locking devices, substantially as described. A

20. In mechanism of the class described, the combination of two groups of racks pivoted in axial alignment, laterall extending arms on the respective racks o the first group, adapted to coact with the corresponding racks of the second group, a pivoted coupler on each arm of the second group, adapted when lowered to engage with the associated arm, a plurality of slotted guide plates associated with said couplers, means for lifting said guide plates to permit said couplers to clear said arms during the movements of the racks of the second group, a main shaft, connections between said main 4shaft and said lifting means for normally effecting a lowering of the latter during the movement of the main shaft to effect engagement between the couplers and the associated arms, a locking device for the racks of the first group, a locking device for the racks of the second group, and a total link adapted when moved to total taking position to unlock the racks of the first group and lock the racks of the second group and hold the coupler guides in non-engaging position during the movement of the operating shaft, substantially as described.

21. In mechanism of the class described, the combination of two groups of racks pivoted in axial alignment, laterally extending arms on the respective racks of the iirst group, adapted to coact with the corresponding racks of the-second group, a pivoted coupler on each arm of the second group, adapted when lowered to engage with the associated arm, a plurality of slotted guide plates associated with said couplers, means for lifting said guide plates to permit said couplers to clear said arms during the movements of the racks of the second group, a main shaft, connections between said main shaft and said lifting means for normally effecting a lowering of the latter during the movement of the main shaft to effect engagement between the couplers and the associated arms, a locking device for the racks of the first group, a locking device for the racks of the second group, a total link adapted when moved to total taking position to unlock the racks of the first group and lock the racks of the second group, and hold the coupler guides in non-en aging position during the movement of t e operatin shaft, and a preparatory device adapte when moved in advance of the movement of the total link to reverse the effect of the latter onthe locking devices, substantially as described.

22. In mechanism of the class described, the combination of two groups of racks in laterally juxtaposed relation, all of the racks being coaxially pivoted, laterally exlUl) tending arms on the racks of the first group, .said arms respectively terminating 1n adpi- Acent relation to the corresponding racks of the second group, a coupler pivoted to each rack of the second group and adapted when lowered to engage the'associated arm, a series of slotted guide plates adapted to raise and lower the couplers to permit advance movement thereof, means for raising and lowering the slotted guide plates en banc, an operating shaft, connections between said operating shaft and the means for raising and lowering the coupler guides, said connections normally permitting engagement of the couplers during the movement of the operating shaft, a locking detent plate for all of the racks of the first group, adapted when raised to engage and lock the same, a locking member adapted when raised to lock the racks of the second group, and a total link adapted when actuated to depress the detent plate and effect release of the racks of the first group and simultaneously to move the locking device for the racks of the second group to locking position, and further adapted to hold the coupler guides in elevated 'position during the movement of the operating shaft, substantially as described.

23. In mechanism of the class described, the combination of two groups of racks in laterally juxtaposed relation, all of the racks being coaxially pivoted, laterally extending arms on the racks of the first group, said arms respectively terminating in adjacent relation to the corresponding racks of the second group, a coupler pivoted to each rack of the second group and adapted when lowered to engage the associated arm, a series of slotted guide plates adapted to raise and lower the couplers and to permit advance movement thereof, means for raising and lowering the slotted guide plates en banc, an operating shaft, connections between said operating shaft and the means for raising and lowering the coupler guides, said connections normally permitting engagement of the couplers during the movement of the operating shaft, a locking detent plate for all of the racks of the first group, adapted when raised to engage and lock the same, a locking member adapted when raised to lock the racks of the second group, a total link adapted when actuated to depress the detent plate and effect release of the racks of the first group and simultaneously to move the locking device for the racks of the second group to locking position, and further adapted to hold the coupler guides in elevated position during the movement of the operating shaft, and a preparatory'device adapted when actuated in advance of the movement of the total link to prevent depression of the locking detent plate, to

`maintain the racks of the first group in locked relation, and to prevent effective movement of the locking device for the racks of the second group to hold said racks in unlocked relation, substantially as described.

BRUCE H. TINGLEY. 

